1. Field of the Invention
The present invention relates generally to chemical reaction catalysts and methods for making and using the same, and more particularly to a catalyst for the production of various organic compounds such as ketones and a method of making the catalyst and using the same in a process of producing the desired ketone. Still more specifically, the present invention relates to use of a theoretical monolayer catalyst to optimize the weight hourly space velocity for a ketone production process in a tube rector.
2. Description of the Prior Art
Numerous literature references cite and disclose various well-known processes for the preparation of ketones. These processes include oxidation of secondary alcohols, Friedel-Crafts acylation, reaction of acid chlorides with organic cadmium compounds, acetoacetic ester synthesis and decarboxylation from acids, among others.
Text and literature references also detail problems associated with these processes to produce ketones. These include problems such as the unavailability and/or cost of raw materials, the requirement of multi-stage processing, the low conversion of raw materials and/or the low selectivity of the desired ketones, and the production of corrosive or hard-to-separate products.
Most ketone manufacturing processes include the reaction of various reactants at specified temperature and pressure ranges in the presence of a catalyst. For example, U.S. Pat. No. 4,528,400 discloses a method of preparing unsymmetrical ketones by a catalytic vapor phase reaction using reactants such as ketones with carboxylic acids in the presence of a ceria-alumina catalyst. U.S. Pat. No. 4,874,899 involves the preparation of unsaturated and saturated ketones in the presence of a catalyst such as a zeolite, a phosphate having a zeolite structure and/or a B, Ce, Fe, Zr or Sr phosphate. U.S. Pat. No. 4,570,021 relates to the preparation of ketones utilizing a ceria-alumina catalyst. U.S. Pat. No. 4,060,555 discloses the production of a class of aliphatic ketones in the presence of Deacon catalysts. U.S. Pat. No. 3,966,822 discloses the preparation of ketones from aldehydes in the presence of zirconium oxide and various other catalysts. U.S. Pat. No. 3,466,334 discloses synthesis of ketones from an aldehyde and an acid in the presence of a catalyst comprised of an alumina-supported oxidized form of lithium. U.S. Pat. No. 3,453,331 discloses a process for the synthesis of ketones from aldehydes using various alumina-supported oxidized forms of various metals. German Patent Application No. P 36 37 788.0 discloses a process for the preparation of a ketone in the presence of catalysts such as ZnO and/or CeO2 doped on aluminum oxide (Al2O3).
Although a great deal of attention has been given to the selection of feed materials and the process parameters such as temperature and pressure in connection with the production of ketones, little, if any, attention has been given to evaluating the role of the catalyst in the ketone preparation process or to selecting or preparing the catalyst for the purpose of maximizing the conversion and selectivity of the feed material to the desired ketone product. Accordingly, there is a need in the art for a catalyst or catalyst structure useful in the production of ketones which not only allows the reaction to proceed, but which also optimizes the conversion and selectivity of the reaction to the desired ketone and permits conversion and selectivity for various catalyst structures to be reasonably predicted. A need also exists in the art for a method of making such a catalyst and for using such a catalyst in the production of ketones.
In contrast to the prior art, the present invention relates to a catalyst and catalyst structure for use in the production of organic compounds such as ketones, which has been formulated to optimize the conversion of feed reactants and selectivity to the desired ketone. Further, the present invention relates to a catalyst and catalyst structure, which enables a dramatic increase in weight hourly space velocity (WHSV) of the production reaction without significantly adversely affecting the conversion and selectivity of the reaction. Still further, a method has been developed in accordance with the present invention for making the above-mentioned catalyst and for using such catalyst in the production of the desired ketone.
More specifically, the catalyst of the present invention comprises a catalyst support having an available or effective surface area of at least about 20 m2 per gram of support or about 20 to 500 m2 per gram of support. As used herein the terms xe2x80x9cavailablexe2x80x9d surface area or xe2x80x9ceffectivexe2x80x9d surface area of a catalyst support is the surface area of a catalyst support that is available to receive at least a monolayer of a selected catalyst. The catalyst structure of the present invention also includes a theoretical monolayer or substantial theoretical monolayer of catalyst applied to the available or effective surface area of the catalyst support. As used herein, the term xe2x80x9ctheoretical monolayerxe2x80x9d means a film layer one molecule thick of a catalyst on the effective surface area of a catalyst support. The present invention recognizes that for reactions involved in the preparation of various organic compounds such as ketones, catalyst supports whose effective surface area is provided with more or less than a theoretical monolayer of the catalyst results in conversion and selectivity values, which are less than optimal.
The present invention also relates to a method of making the above-described catalyst and using the same in the production of ketones. More specifically, the method of making the catalyst involves the steps of providing a catalyst support having an effective surface area of at least 20 m2 or about 20 to 500 m2 per gram of catalyst support and then applying a theoretical monolayer of catalyst to the effective surface area of the catalyst support. The method of using the catalyst includes combining the feed streams of the desired organic compound or ketone producing reaction in the presence of heat, pressure and the catalyst in a reaction vessel, maintaining the feed stream at a rate sufficient for the desired reaction to occur and then separating the desired ketone from the exit stream. With a theoretical monolayer of catalyst, it has been found that the weight hourly space velocity (WHSV) of the reaction can be significantly increased and conversion and selectivity of the desired ketone can be optimized.
Accordingly, it is an object of the present invention to provide an improved catalyst structure for use in the production of organic compounds such as ketones.
Another object of the present invention is to provide a catalyst structure usable in a ketone production process, which optimizes the conversion and selectivity relative to the desired ketone.
Another object of the present invention is to provide a catalyst structure for a ketone production process by which the conversion and selectivity of the desired ketone can be predicted.
A further object of the present invention is to provide a catalyst structure for a ketone production process in which the weight hourly space velocity can be significantly increased.
A still further object of the present invention is to provide a method of making the catalyst structure described above.
A still farther object of the present invention is to provide a method for using the above-described catalyst structure in the production of a desired ketone.
These and other objects of the present invention will become apparent with reference to the drawing, the description of the preferred embodiment and the appended claims.